High blood pressure can occur in pregnancy in two forms. It may be a preexisting condition, called chronic hypertension, or it can develop during pregnancy--a condition known as gestational hypertension. It is also called toxemia or preeclampsia and occurs most often in young women with a first pregnancy.
AC relays. AC relays are manufactured similar to their DC counterparts. If AC current is applied to a DC relay, the relay will pulse at the frequency of the AC current. To overcome this problem, the core is equipped with a shading ring on one-half of the core (Photo 2).
The first circuit is called the control circuit; the second is called the load circuit. There are three basic functions of a relay: On/Off Control, Limit Control and Logic Operation. On/Off Control: Example: Air conditioning control, used to limit and control a high power. load, such as a compressor.